- UNIX usually has a version of GZIP alreadyunstalled on the system. If not, there are four of the more common GZIPprograms on this CD-ROM (Alpha Dec, SGI, Sparc-Solaris 2.5 and 2.6). Thesecan be found in the top directory of this CD-ROM in the GZIP folder underUNIX. If you are on a different system go to www.gzip.org to findthe GZIP program that will work for you.

- Window users may use Winzip to decompressthese files. There is also a freeware Windows version of GZIP on this CD-ROM.This can be found in the top directory of this CD-ROM in the GZIP folderunder Windows.

-Macintosh users may use MacGZIP. There is a copy on this CD-ROM. Thiscan be found in the top directory of this CD-ROM in the GZIP folder underMac.

1. Bathymetry and backscatter data processed onSilicon Graphic computer using software developed by the Ocean Mapping Group,University of New Brunswick. (see USGS OpenFile Report 98-509, The Bathymetry of Lake Tahoe, California-Nevada)2. Processed data downloaded to a Sun Sparc Ultra 2, running Solaris 2.5as an ascii file (longitude, latitude, depth, or backscatter DN value)3. In Arc/Info 7.1.2 a point coverage is created from the ascii file.4. Point coverage is projected into UTM projection.5. Projected point coverage is gridded using IDW (Inverse Distance Weighted)function.6a. Grid is exported to Arc/Info export (.e00) file.6b. Grid is converted to a TIFF image using the "Gridimage" command.7. Both the export and TIFF files are compressed using UNIX version of GZIP.